Check the driven cables that go from the motors to the mechanisms. On my old Volvo, I ended up lubing the cables with high temp grease, and then even going so far as to trim a bit of the sheathing from the ends, so the cable ends bottomed out in the housings at both ends. Never had a problem with it after that. The cable tend to go dry over time, then they bind up in the sheathing. Make sure to lube your seat tracks as well.